blender crashes my entire pc
Your CPU is too hot!  

Why ?
When you ask blender to render, the CPU (and/or GPU) is used at it's maximum (100% usage at max frequency). This produces heat.

What can you do?
Check the air flow.
Global case airflow

The air has to be able to come in and out (clean the grids and case fans for dust) and through (move cables and anything that is in the path).  

CPU Air Flow

Make sure the fan is turning and clean the dust in the fan and heat sink.

You can buy a bigger/better CPU fan/heat sink.
You can use watercooling if it's not enough. (technical and expensive but powerful)